import time
import threading
import traceback
import logging
from pymavlink import mavutil
from MAVProxy.modules.lib import mp_module
from droneapi.lib.WebClient import *
from droneapi.lib import APIConnection, Vehicle, VehicleMode, Location, \
    Attitude, GPSInfo, Parameters, CommandSequence, APIException

# Enable logging here (until this code can be moved into mavproxy)
logging.basicConfig(level=logging.DEBUG)

logger = logging.getLogger(__name__)

class MPParameters(Parameters):
    """
    See Parameters baseclass for documentation.

    FIXME - properly publish change notification
    """

    def __init__(self, module):
        self.__module = module

    def __getitem__(self, name):
        return self.__module.mav_param[name]

    def __setitem__(self, name, value):
        self.__module.mpstate.functions.param_set(name, value)

class MPCommandSequence(CommandSequence):
    """
    See CommandSequence baseclass for documentation.
    """

    def __init__(self, module):
        self.__module = module

    def download(self):
        '''Download all waypoints from the vehicle'''
        self.wait_valid()
        self.__wp.fetch()
        # BIG FIXME - wait for full wpt download before allowing any of the accessors to work

    def wait_valid(self):
        '''Block the calling thread until waypoints have been downloaded'''
        # FIXME this is a super crufty spin-wait, also we should give the user the option of specifying a timeout
        while (self.__wp.wp_op is not None) and not self.__module.api.exit:
            time.sleep(0.200)

    def goto(self, l):
        if l.is_relative:
            frame = mavutil.mavlink.MAV_FRAME_GLOBAL_RELATIVE_ALT
        else:
            frame = mavutil.mavlink.MAV_FRAME_GLOBAL
        self.__module.master.mav.mission_item_send(self.__module.target_system,
                                               self.__module.target_component,
                                               0,
                                               frame,
                                               mavutil.mavlink.MAV_CMD_NAV_WAYPOINT,
                                               2, 0, 0, 0, 0, 0,
                                               l.lat, l.lon, l.alt)

    @property
    def __wp(self):
        return self.__module.module('wp')

    @property
    def count(self):
        return self.__wp.wploader.count()

    @property
    def next(self):
        """
        Currently active waypoint number

        (implementation provided by subclass)
        """
        return self.__module.last_waypoint

    @next.setter
    def next(self, index):
        self.__module.master.waypoint_set_current_send(index)

    def __getitem__(self, index):
        return self.__wp.wploader.wp(index)

    def __setitem__(self, index, value):
        self.__wp.wploader.set(value, index)
        # BIG FIXME - mark as dirty/send on next flush

class MPVehicle(Vehicle):
    def __init__(self, module):
        super(Vehicle,self).__init__()
        self.__module = module
        self._parameters = MPParameters(module)
        self._waypoints = None

    #
    # Private sugar methods
    #

    @property
    def __master(self):
        return self.__module.master

    @property
    def __mode_mapping(self):
        return self.__master.mode_mapping()

    #
    # Operations to support the standard API (FIXME - possibly/probably this
    # will move into a private dict of getter/setter tuples (invisible to the API consumer).
    #

    @property
    def mode(self):
        self.wait_init() # We must know vehicle type before this operation can work
        return self.__get_mode()

    def __get_mode(self):
        """Private method to read current vehicle mode without polling"""
        return VehicleMode(self.__module.status.flightmode)

    @mode.setter
    def mode(self, v):
        self.wait_init() # We must know vehicle type before this operation can work
        self.__master.set_mode(self.__mode_mapping[v.name])

    @property
    def location(self):
        return Location(self.__module.lat, self.__module.lon, self.__module.alt, is_relative=False)

    @property
    def velocity(self):
        return [ self.__module.vx, self.__module.vy, self.__module.vz ]
        
    @property
    def angularRates(self):
        return [ self.__module.pitchspeed, self.__module.rollspeed, self.__module.yawspeed]

    @property
    def attitude(self):
        return Attitude(self.__module.pitch, self.__module.yaw, self.__module.roll)

    @property
    def gps_0(self):
        return GPSInfo(self.__module.eph, self.__module.epv, self.__module.fix_type, self.__module.satellites_visible)

    @property
    def armed(self):
        return self.__module.mpstate.status.armed

    @armed.setter
    def armed(self, value):
        if value:
            self.__master.arducopter_arm()
        else:
            self.__master.arducopter_disarm()

    @property
    def groundspeed(self):
        return self.__module.groundspeed

    @property
    def airspeed(self):
        return self.__module.airspeed

    @property
    def channel_override(self):
        overrides = self.__rc.override
        # Only return entries that have a non zero override
        return dict((str(num + 1), overrides[num]) for num in range(8) if overrides[num] != 0)

    @channel_override.setter
    def channel_override(self, newch):
        overrides = self.__rc.override
        for k, v in newch.iteritems():
            overrides[int(k) - 1] = v
        self.__rc.set_override(overrides)

    @property
    def channel_readback(self):
        return self.__module.rc_readback

    @property
    def __rc(self):
        return self.__module.module('rc')

    @property
    def commands(self):
        """
        The (editable) waypoints for this vehicle.
        """
        if(self._waypoints is None):  # We create the wpts lazily (because this will start a fetch)
            self._waypoints = MPCommandSequence(self.__module)
        return self._waypoints

    @property
    def system_status(self):
        return self.__module.system_status
    @property
    def rssi(self):
        return self.__module.rssi

    def send_mavlink(self, message):
        status = self.__module.mpstate.status
        if hasattr(message, 'target_system'):
            message.target_system = status.target_system
        if hasattr(message, 'target_component'):
            message.target_component = status.target_component
        self.__module.master.mav.send(message)

    @property
    def message_factory(self):
        """
        Returns an object that can be used to create 'raw' mavlink messages that are appropriate for this vehicle.
        These message types are defined in the central Mavlink github repository.  For example, a Pixhawk understands
        the following messages: (from https://github.com/mavlink/mavlink/blob/master/message_definitions/v1.0/pixhawk.xml).

          <message id="153" name="IMAGE_TRIGGER_CONTROL">
               <field type="uint8_t" name="enable">0 to disable, 1 to enable</field>
          </message>

        The name of the factory method will always be the lower case version of the message name with _encode appended.
        Each field in the xml message definition must be listed as arguments to this factory method.  So for this example
        message, the call would be:

        msg = vehicle.message_factory.image_trigger_control_encode(True)
        vehicle.send_mavlink(msg)
        """
        return self.__module.master.mav

    def wait_init(self):
        """Wait for the vehicle to exit the initializing step"""
        timeout = 30
        pollinterval = 0.2
        for i in range(0, int(timeout / pollinterval)):
            # Don't let the user try to fly while the board is still booting
            mode = self.__get_mode().name
            print "mode is", mode
            if mode != "INITIALISING" and mode != "MAV":
                return

            time.sleep(pollinterval)
        raise APIException("Vehicle did not complete initialization")


class MPAPIConnection(APIConnection):
    """
    A small private version of the APIConnection class

    In Mavproxy you probably just want to call get_vehicles
    """
    def __init__(self, module):
        self.__vehicle = MPVehicle(module)

    def get_vehicles(self, query=None):
        return [ self.__vehicle ]

class APIThread(threading.Thread):
    def __init__(self, module, fn, description):
        super(APIThread, self).__init__()
        self.module = module
        self.description = description
        self.exit = False  # Python has no standard way to kill threads, this allows
        self.fn = fn
        self.thread_num = module.next_thread_num
        module.next_thread_num = module.next_thread_num + 1
        self.daemon = True  # For now I think it is okay to let mavproxy exit if api clients are still running
        self.start()
        self.name = "APIThread-%s" % self.thread_num
        self.module.thread_add(self)

    def kill(self):
        """Ask the thread to exit.  The thread must check threading.current_thread().exit periodically"""
        print "Asking %s to exit..." % self.name
        self.exit = True

    def run(self):
        try:
            self.fn()
            print("%s exiting..." % self.name)
        except Exception as e:
            print("Exception in %s: %s" % (self.name, str(e)))
            traceback.print_exc()
        self.module.thread_remove(self)

    def __str__(self):
        return "%s: %s" % (self.thread_num, self.description)

class APIModule(mp_module.MPModule):
    def __init__(self, mpstate):
        super(APIModule, self).__init__(mpstate, "api")

        self.add_command('api', self.cmd_api, "API commands", [ "<list>", "<start> (FILENAME)", "<stop> [THREAD_NUM]" ])
        self.add_command('web', self.cmd_web, "API web connections", [ "<track> (USERNAME) (PASSWORD) (VEHICLEID)",
            "<control> (USERNAME) (PASSWORD) (VEHICLEID)", "<disconnect>" ])
        self.api = MPAPIConnection(self)
        self.vehicle = self.api.get_vehicles()[0]
        self.lat = None
        self.lon = None
        self.alt = None

        self.vx = None
        self.vy = None
        self.vz = None

        self.airspeed = None
        self.groundspeed = None

        self.pitch = None
        self.yaw = None
        self.roll = None
        self.pitchspeed = None
        self.yawspeed = None
        self.rollspeed = None

        self.rc_readback = {}
        self.system_status = None
        self.rssi = None
        self.last_waypoint = 0

        self.eph = None
        self.epv = None
        self.satellites_visible = None
        self.fix_type = None  # FIXME support multiple GPSs per vehicle - possibly by using componentId

        self.next_thread_num = 0  # Monotonically increasing
        self.threads = {}  # A map from int ID to thread object

        self.web = None
        self.web_interface = 0
        self.web_serverid = None
        print("DroneAPI loaded - UCB Custom")

    def __on_change(self, *args):
        for a in args:
            self.vehicle.notify_observers(a)

    def unload(self):
        """We ask any api threads to exit"""
        for t in self.threads.values():
            t.kill()
        for t in self.threads.values():
            t.join(5)
            if t.is_alive():
                print "WARNING: Timed out waiting for %s to exit." % t

    def mavlink_packet(self, m):
        typ = m.get_type()
        if typ == 'GLOBAL_POSITION_INT':
            (self.lat, self.lon) = (m.lat / 1.0e7, m.lon / 1.0e7)
            (self.vx, self.vy, self.vz) = (m.vx / 100.0, m.vy / 100.0, m.vz / 100.0)
            self.__on_change('location', 'velocity')
        elif typ == 'GPS_RAW':
            pass # better to just use global position int
            # (self.lat, self.lon) = (m.lat, m.lon)
            # self.__on_change('location')
        elif typ == 'GPS_RAW_INT':
            # (self.lat, self.lon) = (m.lat / 1.0e7, m.lon / 1.0e7)
            self.eph = m.eph
            self.epv = m.epv
            self.satellites_visible = m.satellites_visible
            self.fix_type = m.fix_type
            self.__on_change('gps_0')
        elif typ == "VFR_HUD":
            self.heading = m.heading
            self.alt = m.alt
            self.airspeed = m.airspeed
            self.groundspeed = m.groundspeed
            self.__on_change('location', 'airspeed', 'groundspeed')
        elif typ == "ATTITUDE":
            self.pitch = m.pitch
            self.yaw = m.yaw
            self.roll = m.roll
            self.pitchspeed = m.pitchspeed
            self.yawspeed = m.yawspeed
            self.rollspeed = m.rollspeed
            self.__on_change('attitude')
        elif typ == "HEARTBEAT":
            self.system_status = m.system_status
            self.__on_change('mode', 'armed')
        elif typ in ["WAYPOINT_CURRENT", "MISSION_CURRENT"]:
            self.last_waypoint = m.seq
        elif typ == "RC_CHANNELS_RAW":
            def set(chnum, v):
                '''Private utility for handling rc channel messages'''
                # use port to allow ch nums greater than 8
                self.rc_readback[str(m.port * 8 + chnum)] = v

            set(1, m.chan1_raw)
            set(2, m.chan2_raw)
            set(3, m.chan3_raw)
            set(4, m.chan4_raw)
            set(5, m.chan5_raw)
            set(6, m.chan6_raw)
            set(7, m.chan7_raw)
            set(8, m.chan8_raw)
            self.rssi = m.rssi
            #Since the RC channels will be changing rapidly, don't issue a callback

        if (self.vehicle is not None) and hasattr(self.vehicle, 'mavrx_callback'):
            self.vehicle.mavrx_callback(m)

        self.send_to_server(m)

    def send_to_server(self, m):
        if (self.web is not None):
            sysid = m.get_srcSystem()
            if sysid != self.web_serverid: # Never return packets that arrived from the server
                try:
                    #logger.debug("send to web: " + str(m))
                    self.web.filterMavlink(self.web_interface, m.get_msgbuf())
                except IOError, e:
                    print "Lost connection to server"
                    # self.web.close()
                    self.web = None
            else:
                #logger.debug("ignore to: " + str(m))
                pass

    def thread_remove(self, t):
        del self.threads[t.thread_num]

    def thread_add(self, t):
        self.threads[t.thread_num] = t

    def cmd_list(self):
        print "API Threads:"
        for t in self.threads.values():
            print str(t)

    def cmd_kill(self, n):
        self.threads[n].kill()

    def get_connection(self):
        return self.api

    def handle_webmavlink(self, msg):
        #print "got msg", msg
        #for m in msg: print "#", hex(ord(m))
        decoded = self.master.mav.decode(msg)
        self.web_serverid = decoded.get_srcSystem()
        #logger.debug("from server: %s (sys=%d, comp=%d, seq=%d)" % (decoded, decoded.get_srcSystem(), decoded.get_srcComponent(), decoded.get_seq()))

        mav = self.master.mav
        # FIXME - mavproxy is slaming in its own sysid - until I fix the generator for mavlinkv10.py to add a sendRaw()
        # instead of the following we send using private state of the mav connection
        #mav.send(decoded)
        mav.file.write(msg)

        if not self.is_controlling:
            # The server wants to send a packet to the vehicle
            mav.total_packets_sent += 1
            mav.total_bytes_sent += len(msg)
            if mav.send_callback:
                mav.send_callback(decoded, *mav.send_callback_args, **mav.send_callback_kwargs)
        else:
            # Pretend that this packet from the server just arrived over a local interface
            mav.total_packets_received += 1
            if mav.callback:
                mav.callback(decoded, *mav.callback_args, **mav.callback_kwargs)

    def web_track(self, username, password, vehicleid):
        """Start uploading live flight data to web service"""
        u = LoginInfo()
        u.loginName = username
        u.password = password
        u.vehicleId = vehicleid

        self.__web_connect(u, False)

    def web_control(self, username, password, vehicleid):
        """Start controlling a vehicle through the web service"""
        u = LoginInfo()
        u.loginName = username
        u.password = password
        u.vehicleId = vehicleid
        # FIXME - this is a super nasty we we find packets the local mavproxy wants to send to server
        # talk with Tridge and construct a better mechanism.  (Possibly make a new 'mav' binding?)
        self.master.mav.set_send_callback(lambda m, master: self.send_to_server(m), self.master)
        self.__web_connect(u, True)

    def web_disconnect(self):
        if self.web is not None:
            self.web.close()
            self.web = None
            print("Disconnected from server")

    def __web_connect(self, u, wantPipe):
        self.web_disconnect() # Drop any old connections
        try:
            self.web = WebClient(u)
            self.web.connect(lambda msg: self.handle_webmavlink(msg), wantPipe = wantPipe)
            self.is_controlling = wantPipe
            print("Connected to server")
        except:
            print("Error, can not connect to server")
            self.web = None

    def cmd_api(self, args):
        if len(args) < 1:
            print("usage: api <list|start|stop> [filename or threadnum]")
            return

        if args[0] == "list":
            self.cmd_list()
        elif args[0] == "stop":
            if len(args) > 2:
                print("usage: api stop [thread-num]")
                return
            elif len(args) > 1:
                self.cmd_kill(int(args[1]))
            elif len(self.threads) > 1:
                # Just kill the youngest
                self.cmd_kill(max(self.threads.keys))
        elif args[0] == "start":
            if len(args) != 2:
                print("usage: api load <filename>")
                return
            g = { "local_connect" : self.get_connection }
            APIThread(self, lambda: execfile(args[1], g), args[1])
        else:
            print("Invalid api subcommand")

    def cmd_web(self, args):
        if len(args) < 1:
            print("usage: web <track|control|disconnect> ...")
            return

        if args[0] == "track":
            self.web_track(args[1], args[2], args[3])
        elif args[0] == "control":
            self.web_control(args[1], args[2], args[3])
        elif args[0] == "disconnect":
            self.web_disconnect()
        else:
            print("Invalid web subcommand")

def init(mpstate):
    '''initialise module'''
    return APIModule(mpstate)
